Advances in the development and improvements of the luminous flux of light-emitting devices such as solid-state semiconductor and organic light-emitting diodes (LEDs) have made these devices suitable for use in general illumination applications, including architectural, entertainment, and roadway lighting. Light-emitting diodes are becoming increasingly competitive with light sources such as incandescent, fluorescent, and high-intensity discharge lamps.
One challenge common to all light sources, and particularly to all light sources used in general and specific illumination applications wherein the visual appearance and/or aesthetics of a given light source may be of importance, or at least of interest, resides in the conceptual, configurational and/or architectural design of a light source which provides adequate lighting for the application while generating minimal visual clutter. In other words, a specific or general purpose light source used in a given environment, such as a luminaire, or the like, should provide adequate lighting while remaining visually pleasing within the context of the given environment.
One type of light source which provides particular challenges in this context are light sources configured to provide an adjustable output, namely with regards to directionality and shape. For instance, various currently available light sources provide such adjustments to the directionality and/or shape of an output beam, but do not provide adequate solutions for providing a visually and aesthetically pleasing design that reduces visual clutter.
For example, U.S. Pat. No. 4,729,077 and U.S. Pat. No. 6,942,363 describe lighting devices having an adjustable lamp direction and output beam width. A reflector and discharge or arc lamp are mounted to an adjustable mount for tilting and panning the lighting device while a position of the lamp is further adjustable relative to the reflector along an optical axis thereof to adjust the output beam width.
U.S. Pat. No. 6,945,671 describes a similar light source mounted on a pivoting support, wherein fluorescent tubes are disposed within a concave reflector at any one of three positions along an optical axis thereof to select a desired output beam width.
Also, in U.S. Pat. No. 5,386,354 a lamp fixture is described to include a lamp fixedly mounted within an adjustable domed reflector configured to pivot relative to a base of the fixture to direct light in a selected direction.
In U.S. Pat. No. 6,193,395 a lighting device is described to comprise two lamp assemblies, each having a respective lamp and output lens, which are adjustably mounted to a base unit via respective internal tracks that allow for the independent orientation of each lamp assembly relative to the base unit. Rotation of a bezel fixedly holding the output lens of a given light assembly moves this output lens relative to the lamp thereby adjusting an output beam width.
Similarly, in U.S. Pat. No. 6,877,876 a variable beam flashlight is described to include a lamp axially movable relative to a fixed output lens, thereby also allowing adjustment of an output beam width.
In U.S. Pat. Nos. 5,907,648 and 6,200,011, luminaires are described to include a light source, such as a lamp or optical fibre assembly, which is moveable relative to a fixed output lens to selectively control output directionality and beam width.
Similarly, in United States Patent Application No. 2005/0018434 a positional luminaire is described to include one or more LEDs moveable via an X, Y and/or Z translation relative to an output lens to again adjust an output directionality and beam width.
Furthermore, other currently available light sources providing an adjustable output have been developed for the automobile industry. One example of an adjustable automobile light source is provided in United States Patent Application No. 2006/0023461 wherein an angle and direction of a light beam generated by a vehicle's spot lights are adjusted for driving conditions and circumstances.
The above examples, however, are generally mainly focused on the adjustability of a light source's output, primarily via a displacement of the light source's lighting element relative to the light source's output optics, while providing little or no attention to its general structural, configurational and/or architectural disposition, and/or overall visual or aesthetic impact on its environment.
Furthermore, typical luminaires, such as track light fixtures and the like, must change shape or spatial position in order to change the direction of the projected light beam. For example, the result of aiming a row of track heads on a track light may generate significant visual clutter, illustratively described as “Dead Bats” by architects and designers.
Consequently, there is a need for an improved light source, such as a luminaire or the like, that addresses some of the drawbacks of known sources.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the invention.